Add the following section to REPORT SUPPORTED OPERATION CODES command.

Transcription

1 Page 1 of 7 Self Describing Cmd Timouts.fm/05-284r4 November 8, 2006 To: INCITS Technical Committee T10 From: Kevin Butt, IBM Date: November 8, :48 pm Document: T10/05-284r4 Subject: SPC-4: Self Describing Command Timeouts 1. Revisions 1. Incorporated feedback received from Rob Elliott on July 21, Incorporate comments from George Penokie and Nov 2005 CAP meeting 3. Modify to use Report Supported Op Codes instead of descriptors. Suggested by George Penokie. 4. Incorporate changes from Sept 2006 CAP meeting 5. Incorporate changes made in Nov 2006 CAP meeting to match r3 as modified that was passed. 2. Introduction The SMC working group has given me an action to create a method to describe the timeout values for each command. I believe this is a more general issue than SMC and belongs in SPC. Additions by this proposal are in this color - blue. Issues to work out are in this color - red. 3. Proposal Add the following section to REPORT SUPPORTED OPERATION CODES command REPORT SUPPORTED OPERATION CODES command introduction The REPORT SUPPORTED OPERATION CODES command (see table 154) requests information on commands the addressed logical unit supports. An application client may request a list of all operation codes and service actions supported by the logical unit or the command support data for a specific command. The REPORT SUPPORTED OPERATION CODES command is a service action of the MAIN- TENANCE IN command. Additional MAINTENANCE IN service actions are defined in SCC-2 and in this standard. The MAINTENANCE IN service actions defined in SCC-2 apply only to

2 Page 2 of 7 Self Describing Cmd Timouts.fm/05-284r4 November 8, 2006 logical units that return a device type of 0Ch or the SCCS bit set to one in their standard INQUIRY data (see 6.4.2). TABLE 154. REPORT SUPPORTED OPERATION CODES command 0 OPERATION CODE (A3h) 1 SERVICE ACTION (0Ch) 2 RCPT REPORTING OPTIONS 3 REQUESTED OPERATION CODE 4 (MSB) REQUESTED SERVICE ACTION 5 6 (MSB) ALLOCATION LENGTH CONTROL A Return Command Processing Time (RCPT) bit set to one specifies that the Command Timeouts descriptor (see Section ) shall be included in each Command descriptor that is returned and to the One_command parameter data that is returned. A RCPT bit set to zero specifies that the Command Timeouts descriptor shall not be included in any parameter data returned. The REPORTING OPTIONS field (see table 155) specifies the information to be returned in the parameter data. TABLE 155. REPORT SUPPORTED OPERATION CODES REPORTING OPTIONS field Code 000b 001b A list of all operation codes and service actions supported by the logical unit shall be returned in the all_commands parameter data format. The REQUESTED OPERATION CODE CDB field and REQUESTED SERVICE ACTION CDB field shall be ignored. The command support data for the operation code specified in the REQUESTED OPERATION CODE field shall be returned in the one_command parameter data format. The REQUESTED SERVICE ACTION CDB field shall be ignored. If the REQUESTED OPERATION CODE field specifies an operation code that has service actions, then the command shall be terminated with CHECK CONDITION status, with the sense key set to ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD IN CDB. Parameter Data Reference

3 Page 3 of 7 Self Describing Cmd Timouts.fm/05-284r4 November 8, b 011b-111b The command support data for the operation code and service action specified in the REQUESTED OPERATION CODE CDB field and REQUESTED SERVICE ACTION CDB field shall be returned in the one_command parameter data format. If the REQUESTED OPERATION CODE CDB field specifies an operation code that does not have service actions, then the command shall be terminated with CHECK CONDITION status, with the sense key set to ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD IN CDB. The REQUESTED OPERATION CODE field specifies the operation code of the command to be returned in the one_command parameter data format (see ). The REQUESTED SERVICE ACTION field specifies the service action of the command to be returned in the one_command parameter data format. The ALLOCATION LENGTH field is defined in Command Timeouts Descriptor The Command Timeouts descriptor returns timeout information for commands supported by the logical unit based on the time from the start of processing the command, to its reported completion. Values returned in this descriptor do not include times that are outside the control of the device server (e.g., a prior command with the IMMED bit set to one in the CDB, concurrent commands from the same or different I_T nexuses, manual unloads, power-on self tests, commands issued after aborted commands, commands which force cache synchronization, delays in the service delivery subsystem). For commands that cause a change in power condition (see ), these times do not include the power condition transition time (e.g., the time to spinup rotating media). The values in this descriptor should not be used to compare products. The Command Processing Times descriptor is described in Table 156 TABLE Command Processing Times descriptor (MSB) 1 Code TABLE 155. REPORT SUPPORTED OPERATION CODES REPORTING OPTIONS field Descriptor Length (0Ah) 2 3 Restricted (Defined in command set specific standards) Parameter Data Reference

4 Page 4 of 7 Self Describing Cmd Timouts.fm/05-284r4 November 8, (MSB) 7 8 (MSB) 11 A non-zero value in the NOMINAL COMMAND PROCESSING TIME field specifies the minimum amount of time in seconds the application client should wait prior to querying for progress for the command specified by the CDB OPERATION CODE and CDB SERVICE ACTION fields. A value of zero in the NOMINAL COMMAND PROCESSING TIME field indicates that no time is being specified. Note: The value specified in the NOMINAL COMMAND PROCESSING TIME field may include time required for typical device error recovery procedures expected to occur on a regular basis. A non-zero value in the RECOMMENDED COMMAND TIMEOUT field specifies the recommended time in seconds the application client should use when timing out the command specified by the CDB OPERATION CODE and CDB SERVICE ACTION fields. A value of zero in the RECOMMENDED COMMAND TIMEOUT field indicates that no time is being recommended. The device server should set the RECOMMENDED COMMAND TIMEOUT field to a value greater than or equal to the NOMINAL COMMAND PROCESSING TIME field All_commands parameter data format NOMINAL COMMAND PROCESSING TIME RECOMMENDED COMMAND TIMEOUT The REPORT SUPPORTED OPERATION CODES all_commands parameter data format (see table 156) begins with a four-byte header that contains the length in bytes of the parameter data followed by a list of supported commands. Each command descriptor contains information about a single supported command CDB (i.e., one operation code and service action combination, or one non-service-action operation code). The list of command descriptors shall contain all commands supported by the logical unit. TABLE 157. All_commands parameter data 0 (MSB) 3 4 TABLE Command Processing Times descriptor COMMAND DATA LENGTH (n-3) Command descriptors Command descriptor 0 (see table 158)...

5 Page 5 of 7 Self Describing Cmd Timouts.fm/05-284r4 November 8, 2006 TABLE 157. All_commands parameter data n Command descriptor x (see table 158) The COMMAND DATA LENGTH field indicates the length in bytes of the command descriptor list. Each command descriptor (see table 158) contains information about a single supported command CDB. TABLE 158. Command descriptor format 0 OPERATION CODE 1 2 (MSB) 3 SERVICE ACTION 4 5 CPTDP SERVACTV 6 (MSB) CDB LENGTH Command Processing Times descriptor (if any) The OPERATION CODE field contains the operation code of a command supported by the logical unit. The SERVICE ACTION field contains a supported service action of the supported operation code indicated by the OPERATION CODE field. If the operation code indicated in the OPERATION CODE field does not have a service actions, the SERVICE ACTION field shall be set to 00h. A service action valid (SERVACTV) bit set to zero indicates the operation code indicated by the OPERATION CODE field does not have service actions and the SERVICE ACTION field contents are reserved. A SERVACTV bit set to one indicates the operation code indicated by the OPERATION CODE field has service actions and the contents of the SERVICE ACTION field are valid. A command processing time descriptor present (CPTDP) bit set to one indicates that the Command Processing Times descriptor shall be included in the data. A CPTDP bit set to zero indicates that the Command Processing Times descriptor shall not be included in the data.

6 Page 6 of 7 Self Describing Cmd Timouts.fm/05-284r4 November 8, 2006 The CDB LENGTH field contains the length of the command CDB in bytes for the operation code indicated in the OPERATION CODE field, and if the SERVACTV bit is set to the service action indicated by the SERVICE ACTION field. If the RCPT bit of the REPORT SUPPORTED OPERATION CODES CDB is set to one, the Command Processing Times descriptor (see Table 158) shall be included. If the RCPT bit of the CDB is set to zero, the Command Processing Times descriptor shall not be included One_command parameter data format The REPORT SUPPORTED OPERATION CODES one_command parameter data format (see table 159) contains information about the CDB and a usage map for bits in the CDB for the command specified by the REPORTING OPTIONS, REQUESTED OPERATION CODE, and REQUESTED SERVICE ACTION fields in the REPORT SUPPORTED OPERATION CODES CDB. The SUPPORT field is defined in table 160. TABLE 159. One_command parameter data 0 1 CPTDP SUPPORT 2 (MSB) CDB SIZE (n-3) 3 4 n CDB USAGE DATA n+1 n+12 Command Processing Times descriptor (if any) TABLE 160. SUPPORT values Support 000b 001b 010b 011b 100b Data about the requested SCSI command is not currently available. All data after byte 1 is not valid. A subsequent request for command support data may be successful. The device server does not support the requested command. All data after byte 1 is undefined. The device server supports the requested command in conformance with a SCSI standard. The parameter data format conforms to the definition in table 159.

7 Page 7 of 7 Self Describing Cmd Timouts.fm/05-284r4 November 8, 2006 Support 101b 110b - 111b The device server supports the requested command in a vendor specific manner. The parameter data format conforms to the definition in table 159. TABLE 160. SUPPORT values A command processing time descriptor present (CPTDP) bit set to one indicates that the Command Processing Times descriptor shall be included in the data. A CPTDP bit set to zero indicates that the Command Processing Times descriptor shall not be included in the data. The CDB SIZE field contains the size of the CDB USAGE DATA field in the parameter data, and the number of bytes in the CDB for command being queried (i.e., the command specified by the REPORTING OPTIONS, REQUESTED OPERATION CODE, and REQUESTED SERVICE ACTION fields in the REPORT SUPPORTED OPERATION CODES CDB). The CDB USAGE DATA field contains information about the CDB for the command being queried. The first byte of the CDB USAGE DATA field shall contain the operation code for the command being queried. If the command being queried contains a service action, then that service action code shall be placed in the CDB USAGE DATA field in the same location as the SERVICE ACTION field of the command CDB. All other bytes of the CDB USAGE DATA field shall contain a usage map for bits in the CDB for the command being queried. The bits in the usage map shall have a one-for-one correspondence to the CDB for the command being queried. If the device server evaluates a bit in the CDB for the command being queried, the usage map shall contain a one in the corresponding bit position. If any bit representing part of a field is returned as one, all bits for the field shall be returned as one. If the device server ignores or treats as reserved a bit in the CDB for the command being queried, the usage map shall contain a zero in the corresponding bit position. The usage map bits for a given CDB field all shall have the same value. For example, the CDB usage bit map for the REPORT SUPPORTED OPERATION CODES command is: A3h, 0Ch, 03h, FFh, FFh, FFh, FFh, FFh, FFh, FFh, 00h, 07h. This example assumes that the logical unit only supports the low-order three bits of the CDB CONTROL byte. The first byte contains the operation code, and the second byte contains three reserved bits and the service action. The remaining bytes contain the usage map. If the RCPT bit of the REPORT SUPPORTED OPERATION CODES CDB is set to one, the Command Processing Times descriptor (see Table 158) shall be included. If the RCPT bit of the CDB is set to zero, the Command Processing Times descriptor shall not be included.